Nuclear Decay Calculator with Steps
Use this nuclear decay calculator to find the daughter nucleus after alpha decay, beta-minus decay, beta-plus decay, electron capture, or gamma decay. This tool only allows radioactive parent elements, helping students practise nuclear equations more accurately.
Calculate Alpha, Beta, or Gamma Decay
This list includes elements with no stable isotopes: Technetium, Promethium, and elements 84–118.
Worked Example: Alpha Decay
How Nuclear Decay Works
Nuclear decay changes the nucleus of an atom. In a balanced nuclear equation, the total mass number and atomic number must be conserved on both sides of the equation.
Beta-minus decay: A same, Z + 1
Beta-plus decay: A same, Z − 1
Electron capture: A same, Z − 1
Gamma decay: A same, Z same
Alpha and beta decay change the identity of the element. Gamma decay releases energy but does not change the mass number or atomic number.
Practice Question
Thorium-234 has mass number 234 and atomic number 90. If it undergoes beta-minus decay, what is the daughter atomic number?